1. Field of the Invention
The present invention relates to a motorcycle having a grab bar, and more particularly to an attachment structure for attaching the grab bar to a body frame of the motorcycle.
2. Description of Related Art
Conventional motorcycles have a grab bar disposed at a rear end of a seat and grabbed by a rear seat rider. The rear seat rider applies a push-down force during acceleration and a pull-up force during braking to the grab bar. Therefore, the grab bar must have sufficient attachment strength and rigidity to the body frame. The structure shown in JP-A-2003-127935, for example, has left and right attachment sections that are located at the front ends of left and right grab sections and extend inward in the vehicle width direction. In this structure, the attachment sections are inserted toward the inside through a space between notches of side covers covering the lower regions of the seat and side edges of the seat, and are fixed to the body frame by bolts.
In such a motorcycle, application of a strong force by the rear seat rider to the grab bar in the front-and-rear direction generates a bending force in the front-and-rear direction and a twisting force around an axis extending in the vehicle width direction on the boundary between the attachment sections and the grab sections. Therefore, to provide a grab bar with sufficient attachment strength and rigidity, the size and wall thickness of the attachment sections must be increased, which in turn increases the weight and cost of the motorcycle.
Moreover, in the structure described above, the notches on the side covers, through which the attachment sections are inserted, are visible from the vehicle side and deteriorate the external appearance of the motorcycle.